3. why is active transport necessary for the sodium-potassium pump to work? a. the sodium would never leave a cell while potassium can move against the gradient b. the potassium would never leave a cell while sodium can move against the gradient c. it allows sodium and potassium to move against their concentration gradient d. all channel movement requires active transport to equalize the cell

Active transport necessary for the sodium-potassium pump to work because  It allows sodium and potassium to move against their concentration gradient.

Explanation:

The transport of sodium ions outside the cell and potassium ions inside the cells is called active transport that requires the ATP hydrolysis. ATP provides the energy required for this procedure. This sodium-Potassium pump works to move the ions against their concentration gradient to keep the sodium concentration low inside the cells and potassium concentration high inside the cells.